$\dfrac{8}{10} - \dfrac{6}{12} = {?}$
Answer: $ = {\dfrac{8 \times 6}{10 \times 6}} - {\dfrac{6 \times 5}{12 \times 5}} $ $ = {\dfrac{48}{60}} - {\dfrac{30}{60}} $ $ = \dfrac{{48} - {30}}{60} $ $ = \dfrac{18}{60}$